The DS Series is closely related to the DSX. Tough as hell, extremely quiet, and quite possibly the most enjoyable shooting experience you’ve had thanks to the M-Kore Technology. The DS is what we recommend when you’re not running anything below a 10.3” barrel, no matter what torture you put it through. Plus, it’s rated for full-auto shooting. The main differences from the DSX are the absence of the secondary tube retention ring and the use of Grade 9 titanium on the tube instead of Grade 5. Grade 5 titanium is much more expensive, and it simply isn’t needed in the DS series.